1. Field of the Invention
The invention relates to a method for automated grouping of objects which are placed in a steady conveying flow in random order onto a conveyor belt and transported to a grouping device, wherein a recognition device determines the location and the position of the arriving objects on the conveyor belt and communicates these to a control unit, that takes into account the belt speed, of a handling device which sorts the objects in a grouped ordered state.
2. Description of the Related Art
The automated handling is coordinated by a control unit of the grouping device. A recognition device detects the location and the position of the arriving objects on the conveyor belt and communicates these continuously to the control unit which, taking into account the belt speed, generates control commands for a handling device. In this context it is conventional to determine, based on the recognized location and position of the arriving objects, for each object the virtual footprint position on the conveyor belt in the area of reach of the handling device. Based on the virtual information and the belt speed, the actual location and position of the considered objects is determined in which, upon being moved at the belt speed, they are positioned in the area of reach of the handling device at a predetermined access time. Within its area of reach, the handling device can be advanced to each object and can sort them in the predetermined grouped ordered state onto a further conveyor belt. It is known that also large quantities of randomly supplied objects can be sorted when the handling device removes the objects from the conveyor belt and places them onto a further conveyor belt, i.e., the sorting belt. The handling device compiles the objects on the sorting belt according to a predetermined sorting specification. The objects are then further transported on the sorting belt positioned in groups of the sorted ordered state.
It is an object of the present invention to provide a method for automated grouping of objects of the aforementioned kind which operates quickly and can be performed with minimal apparatus expenditure.
In accordance with the method of the invention, the objects are grouped on the conveyor belt and further transported thereon, wherein the control unit evaluates the random ordered state on the conveyor belt and determines the location of a group on the conveyor belt.
The invention is based on the recognition that between the randomly arranged objects on the conveyor belt there are surface areas provided which are also randomly positioned and on which sorted objects can be placed in groups. Moreover, by means of the handling of individual objects supplemental surface areas will be freed which subsequently can be used for grouping of further objects. In the inventive method, the control unit evaluates via the detection of the respective location and position of the arriving objects the random ordered state of all objects on the conveyor belt and determines based thereon randomly available sorting positions with sufficient surface area for a respective group. The objects are sorted on the conveyor belt and are farther transported in groups so that the apparatus expenditure that was required up to now for performing the automated grouping method is reduced. In particular, the sorting belt that was required up to now can be eliminated because the conveyor belt itself forms the sorting belt. Moreover, with the method according to the invention, the efficiency of the grouping device is increased because the handling device must travel, on average, short distances for sorting the arriving objects so that the grouping process can be performed quickly.
Advantageously, an object is selected as a recognition object which determines the sorting position, with further objects being sorted next to it according to the predetermined grouping order. The recognition object remains in its original random position on the conveyor belt during sorting so that for the grouping action only the further objects must be handled. The grouping of the objects on the conveyor belt can be performed very quickly because one handling step per group is eliminated, i.e., that of the recognition object.
The further objects of a group can be aligned based on the position of the recognition object. The random location of the recognition object determines the location of the further objects which in the considered group are compiled according to the predetermined correlation specification. The sorted objects are thus respectively positioned within their groups according to the predetermined ordered state in which they are transported to further processing, if needed. The position and the orientation of each group depends on the position and the location of the recognition objects, wherein the groups can also be arranged adjacent to one another on the conveyor belt and the transport efficiency of the conveyor belt can be taken advantage of in this way. The presence of several sorted groups adjacent to one another is probable given the randomness of the orientation so that the available width of the conveyor belt can be fully used.
Advantageously, the control unit processes the randomly ordered state on the conveyor belt such that, if needed, the location of the selected recognition object can be corrected, for example, for providing a situation beneficial for the subsequent grouping. A correction of the location of the selected recognition object via a respective control of the handling device is carried out also when the processing result of the randomly ordered state indicates that the selected recognition object is positioned adjacent to the edge of the conveyor belt and the surface area corresponding to the determined location is insufficient for positioning the predetermined number of further objects of the considered group. Those objects which in the ordered state as supplied are positioned on the conveyor belt with a spacing as minimal as possible to the determined sorting position (recognition object) are advantageously correlated with the respective group so that correspondingly short distances are required of the handling device during sorting.